1. Technical Field
The present invention relates to a pogo-type probe to be installed in a probe socket and a probe card. More particularly, the present invention relates to a pogo probe having crown-shaped probe heads for testing semiconductor devices for chip scale package.
2. Description of Related Art
Conventionally, an integrated circuit component is tested with vertical or cantilever probes installed in a probe socket, which is vertically attached on a printed circuit board to form a probe card for testing. Positional accuracy of the probes is maintained by the edge shape of the probe socket. Then, deflection that results from contact between the probes and the semiconductor device under test facilitates compression to the extent required for testing. However, the deflection is insufficient for compensation for errors in flatness of the semiconductor device under test or related hardware, and thus problems associated with poor contact tend to occur during testing.
U.S. Pat. Nos. 6,220,870, 6,464,511 and 6,685,492 disclose a crown-shaped probe head, so that a probe can be designed with crown-shaped, rather than flat, tips to increase the reliability of contact between the probe and solder balls. In addition, probe cards produced by manufacturing giants such as FormFactor and Feinmetall use probes that deflect only to a limited extent (less than 0.15 mm) when contacting a semiconductor device under test. Hence, errors in flatness between the probes and the semiconductor device under test cannot be improved. In other words, all the aforementioned prior art fails to solve the problem of conventional probe cards, namely poor contact and the resultant compromised test reliability because of non-flatness at relative level between conventional probes and a semiconductor device under test during testing.
As mentioned above, the configuration of conventional probes and the way conventional probes are attached on a probe socket or a probe card have become a source of inconvenience and troubles for test operators during testing. Therefore, it is an urgent issue in the related industry to provide a convenient and effective probe, probe socket and probe card that can be easily used by test operators and can prevent the foregoing shortcomings of the prior art.